I read somewhere else some time ago that DVD Media is manufactured differently in the sense that the reflective layer is hard to damage as it is protected by a thick layer of plastic whereas the CD’s just have the reflective layer exposed and it can be damaged fairly easily.
Can anyone can confirm or deny this DVD Media fact?
No optical media has the reflective layer exposed. DVD are easire to scratch in my experience, and scratches cause more reading problems than on CDs. There’s a difference between scratches on the back of the disc, where the reflective layer would get damaged, and scratches on the burn-side, where reading issues come in. All things considered, I think iit’s a toss-up for the 2 types. One may be more resistant on the back side but more fragile on the burn side.
rdgrimes, I think I need to clarify what I meant about the reflective layer exposed. I am also only referring to damage to the reflective layer (I feel with careful handling the burn layer can be protected, by with CDRs with a poor top coating that peels you are defenseless…).
I realize the reflective layer is not directly exposed, but with many CDRs I have seen the top peel off, and along it usually is a portion of the reflective layer causing the data to be lost :(.
In a post I read here, someone said DVD’s use 3 layers of plastic and a layer of plastic at the top would have to be penetrated before the reflective layer could be affected, is that true?
I’ll try and find the post to show you exactly what my point is.
I am a newbie and a few days ago, I saw a DVD-R for the first time in my life.
I soon noticed that there were two polycarbonate (plastic) layers on both sides, protecting the recording dye. Now you cannot damage the recording dye from the top.
CD-R only has one layer of plastic on the bottom side. In the top side there is nothing to protect the recording dye. In fact, if you touch the top side with your nail, and you look at the bottom side, you can see the pressure being applied to the dye.
In DVD-R, there are 2 layers of plastic, and you can see it in the outer and inner limits of the disc. Both layers are somewhat “glued” together. In fact, there is “glue” flooding out, in the outer edge.
both CD’s and DVD’s are 1.2mm thick, the difference is:
the laser need to pass for 1.2mm to reach the data, which is the whole disc thickness, and on the top the recording layer + protective layer, and any small scratch that hit’s the recording layer damages data.
the laser need to pass only 0.6mm to read the data, so there is 0.6mm plastic, then recording layer, then another 0.6mm plastic, so the recording layer is well protected, and not as easily damaged as CD’s.
the 0.6mm is the reason why there are double sided DVD’s.
Once I got a 100 pack of cd’s which after a while, the silver would peel off… Caused a lot of read errors… So I peeled it all off and made the entire CD transparent… So now no read errors and it works fine… I am not sure it would have burnt without the coating though. Easy way to check if the coating comes off is to stick a tape on the top and peel it… Then try reading it I have a few DVD’s where the top does not have any coating, it looks like someone put some glass on top of a CD… The silver seems to be in the middle so cant peel it off The TDK +R media is like that but not as good as the navtech in looks.
Thank you everyone. This is exactly my point and the information I was trying to veriy. I sure hate how CDRs peel so damn easily and I’m glad I can go ahead and buy silver DVD media without any disadvantage.